Hey there, Destiny 2 game data is tied to the platform account not the Bungie Account - meaning that the character data (progress, inventory) is tied directly to the old XBox account that you no longer have access to. Bungie Accounts hold things like your redeemed emblem codes, and Bungie digital rewards, but not your characters or your game data. This is not something that has been affected by the unlink update. In a situation where it had not happened, to swap the current XBox account for the new XBox account would still mean starting out from nothing, the characters would be gone. Additionally it had never been possible to unlink accounts you don't have access to. There was never any outcome that could let you use those old XBox characters on another XBox account. So the characters are lost because you've lost access to the old account and despite the time and money invested into it, chose to make a new one instead of recovering it.